Problem: What is the greatest common factor of $24$ and $30$ ? Another way to say this is: $\operatorname{gcf}(24, 30) = {?}$
Solution: The greatest common factor is the largest number that is a factor of both $24$ and $30$ The factors of $24$ are $1$ $2$ $3$ $4$ $6$ $8$ $12$ , and $24$ The factors of $30$ are $1$ $2$ $3$ $5$ $6$ $10$ $15$ , and $30$ Thus, the greatest common factor of $24$ and $30$ is $6$. $\operatorname{gcf}(24, 30) = 6$